Italy are expected to start Ciro Immobile, Lorenzo Insigne and Federico Chiesa, while Portugal rely on Andre Silva, Joao Cancelo and Mario Rui.
The Nations League match kicks off at San Siro in Milan at 19.45 GMT.
The Nazionale can still win the group, but must beat Portugal and hope that Poland win the final game on Tuesday.
Another possible route is to win by two clear goals this evening, so a draw between Poland and Portugal would be enough.
Italy are expected to start Ciro Immobile, Lorenzo Insigne and Federico Chiesa, while Portugal rely on Andre Silva, Joao Cancelo and Mario Rui.
The Nations League match kicks off at San Siro in Milan at 19.45 GMT.
The Nazionale can still win the group, but must beat Portugal and hope that Poland win the final game on Tuesday.
Another possible route is to win by two clear goals this evening, so a draw between Poland and Portugal would be enough.
It is practically the same line-up that beat Poland last month, but missing injured Juventus winger Federico Bernardeschi.
Although Domenico Berardi was floated as an option to keep Insigne as a centre-forward, but instead it looks as if Immobile will be chosen, moving the Napoli player back to his old role on the left flank.
Immobile has seven goals in 33 senior Italy caps, but fired blanks in his last eight appearances, last finding the net in a 1-0 World Cup qualifier against Israel in September 2017.
Fiorentina star Federico Chiesa remains on the right of the trident.
It’s a special game for Giorgio Chiellini, who will be making his 100th Italy appearance precisely 14 years after his debut.
Alessio Romagnoli was expected to start in Tuesday’s friendly against the USA in Genk, but the Milan defender pulled out with a muscular problem.
Portugal must do without suspended captain Pepe, while Andre Gomes pulled out of the squad with injury and Raphael Guerreiro only just resumed training following a muscular problem yesterday.
Milan-owned Andre Silva again leads the attack, having scored the winner when these teams met in September and rediscovered his confidence on loan at Sevilla.
The 23-year-old has an extraordinary record with the Seleçao, scoring 14 goals in just 29 senior caps, finding the net in each of his last two games.
He’ll likely be flanked by Benfica forward Pizzi and RB Leipzig talent Bruma.
The full-backs are both Serie A representatives, Joao Cancelo of Juventus and Napoli’s Mario Rui.
Wolves midfielder Ruben Neves is eager to prove a point after he was dropped from the 2018 World Cup squad.
Italy play the United States in a friendly on Tuesday at Genk’s Luminus Arena, Belgium.
Italy (probable): Donnarumma; Florenzi, Bonucci, Chiellini, Biraghi; Barella, Jorginho, Verratti; Chiesa, Immobile, Insigne
Portugal (probable): Rui Patricio; Cancelo, Fonte, Ruben Dias, Mario Rui; Ruben Neves, William Carvalho, Bernardo Silva; Pizzi, Andre Silva, Bruma